The present invention relates generally to implanting cattle and in particular relates to implanting of drugs into feed animals to increase the size of the animal prior to slaughter.
Cattle farmers uniformly implant cattle with growth hormones or steroids due to the higher feed efficiency, added weight gains, and lower cost per animal than a feed mix or other method. The implants are approved by the U.S. Food and Drug Administration (USFDA) and must be implanted, under such approval, in a specific location in the back of the ear of the animal between the hide and the first layer of tissue. The placement of the implant in the proper location permits the proper time release of the steroid or growth hormone into the animal. The cost of the implants is over $2.00 per head of cattle over an eight to nine month period over which period each head of cattle will gain an extra thirty to fifty pounds.
The process generally involves confining the animal to be implanted in a squeeze chute, loading the implant in an injector, grasping the tip of the animal's ear in one hand and the injector in the other, penetrating under the skin with the needle of the injector on the back side of the middle third of the animal's ear, fully inserting the needle between the skin and cartilage while avoiding major blood vessels, pulling the needle back (to remove the needle) as the plunger of the injector is pushed forward to place the implant in the ear of the animal. Optional hygiene techniques may also add steps at various points in the process.
To protect against infection due to the breakage of the skin or hide, some implants have an antibiotic coating, such as that used in COMPUDOSE, an estradiol sold by the Elanco Division of Eli Lilly & Co., approved for steers and calves and having a 200 day period of usefulness. The antibiotic coating, however, has a silicone base which causes a significant percentage of the implants to be expelled by the animal from its ear prior to the healing of the hide at the insertion point. Expulsion of the implant not only costs the farmer the expense of the implant, but also causes the farmer to lose the income he would have acquired from the thirty to fifty pounds of meat that each head of cattle would have acquired if the implant had remained in place the entire period of desired implantation. Other implants having a shorter term of usefulness than COMPUDOSE are sold under the trade names RALGRO (by International Minerals & Chemical Corporation, Terre Haute, Indiana) and SYNOVEX (by Syntex Corp.).
The present invention seeks to improve the implantation technique and the retention level of the implants in the animals. A retainer has been developed by applicants which can be inserted along with the implant to retain the antibiotic coated implant in the ear with great success. The retainer has the object of improving its effectiveness in direct proportion to the conditions that had decreased the effectiveness of the implant without the retainer, particularly becoming increasingly effective as the implant moves in a direction towards the hole caused by the injector needle during implantation.
Further, a packaged set of the retainers has been developed, which is insertable into an injector also developed by applicants, to conveniently implant the drug and the retainer into the ears of cattle in a large scale operation. Packaging of the implants and retainers in the same cartridge is also within the scope of the invention.
The injector of the present invention has the additional advantages of a gravity feed for the retainers and implants, universatility for right-handed or left-handed use of the injector by the operator, and the convenience of a requirement that only one hand need be used to operate the injector during the implantation process.
The method of implanting is also improved by the implantation of the retainer and implant together, particularly when used in connection with the injector of the present invention.
Other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.